While Windows 8 PCs were ubiquitous at this year's Consumer Electronics Show, Microsoft Surface tablets are poised to take over, according to one prediction.

"If Microsoft is successful then it could be the world's biggest Windows (device maker) in just a few years," Tom Warren, who covers Microsoft for tech site The Verge, wrote Sunday. "The future is Surface."

Meanwhile, analysis firm Gartner reported Monday that fourth-quarter PC shipments were down 4.9 percent worldwide and 2.1 percent in the U.S. from a year earlier.

Tablets have dramatically changed the device landscape for PCs, not so much by 'cannibalizing' PC sales, but by causing PC users to shift consumption to tablets rather than replacing older PCs," principal Gartner analyst Mikako Kitagawa wrote.

Whereas as once we imagined a world in which individual users would have both a PC and a tablet as personal devices, we increasingly suspect that most individuals will shift consumption activity to a personal tablet, and perform creative and administrative tasks on a shared PC. There will be some individuals who retain both, but we believe they will be exception and not the norm. Therefore, we hypothesize that buyers will not replace secondary PCs in the household, instead allowing them to age out and shifting consumption to a tablet.

The success of Surface -- and, more so, Microsoft's Surface with Windows 8 Pro, which starts at $899 -- remains very much an open question. But a future world where people forgo PCs in favor of a tablet, rather than using both, speaks to Microsoft's beefy tablet vision.